The present invention relates to a number printing machine, and more particularly to a number printing machine which is capable of perform a number printing and a perforation.
In general, a printing machine having both a number printing function and a perforation function.
In this type conventional printing machine, a pressure drum is provided downstream of a paper feed section. A rubber drum comes into contact with the pressure drum. A printing drum is in contact with the rubber drum. A water supply unit and an ink supply unit are brought into contact with the printing drum. A delivery drum is provided on the pressure drum, and a numbering pressure drum is brought into contact with the delivery drum. A lateral perforation blade for forming a lateral perforation, a longitudinal perforation blade for forming a longitudinal perforation and a numbering box are brought into contact with the numbering pressure drum. Furthermore, a paper discharge section is provided downstream of the numbering pressure drum. An ink feeder for numbering is used to supply the numbering box with ink.
A drum attachment paper is tensioned so as to come into intimate contact with the numbering pressure drum by a tension mechanism (not shown) with its one end being attached by screws to a drum attachment paper fixing member provided in a recess formed in the numbering pressure drum, and with the other end being fixed to a fastening bar. A lateral perforation band (not shown) corresponding to the above-described lateral preformation blade is provided in the axial direction of the numbering pressure drum on an outer periphery of the drum attachment paper, whereas a longitudinal perforation band corresponding to the longitudinal perforation blade is wound in the circumferential direction on the outer periphery of the drum attachment paper and is made of polished steel plate. One end of the longitudinal perforation band made of steel is clamped by longitudinal band fasteners. The other end of the longitudinal perforation band is provided with a number of retainer holes. A spring is hooked at one of the retainer holes for applying a tension to the longitudinal perforation band.
The lateral perforation blade, the longitudinal perforation blade and the numbering box are finely arranged relative to the numbering pressure drum so that a delicate contact pressure may be obtained.
In the printing machine with such an arrangement, however, as described above, the lateral and longitudinal perforation bands corresponding, respectively, to the lateral and longitudinal blades are provided with a tension on the drum attachment paper in the lateral and longitudinal directions, and in addition, in many cases, the lateral and longitudinal perforation bands are made of steel with a Thickness of 0.5 mm. As a result, the bands projects on the drum attachment paper by a distance corresponding to the thickness of the bands. When the printing paper is delivered on the numbering pressure drum, the printing paper is subjected to corrugations by the projection of the lateral perforation band when the longitudinal perforation is formed by the longitudinal perforation blade and by the projection of the longitudinal perforation band when the lateral perforation is formed by the lateral perforation blade. Thus, the paper is not kept exactly fit to the numbering pressure drum. Thus, the prior art machine suffers from a defect that the misaligned or serpentine perforation would appear in the printing paper.
Also, when the numbers are printed on the printing paper on the numbering pressure drum by the numbering box, the printing paper would be lifted or floated by the respective perforation bands in the same manner and would be subjected to the corrugation. It is thus difficult to obtain a good numbering print with high positional precision.
Furthermore, in the above-described arrangement, since the three functional units such as a lateral perforation blade, a longitudinal perforation blade and a numbering box are located in a narrow space so as to surround the numbering pressure drum, the operational property would be worse and it takes a long time to adjust or set these units in place. In addition, since the numbering pressure drum is come into alignment with the numbering box only when the paper is fed to the numbering pressure drum, the adjusted pressure between the lateral perforation blade and the numbering pressure drum is varied due to the movement of the numbering pressure drum.